The Brief Symptom Inventory (BSI) - Service correctionnel du Canada

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Levin & Gianan, 1995). However, some studies have found little evidence for the number of dimensions (Schwannauer & Chetwynd, 2007). References to studies on the validity of the BSI are found in the manual (Derogatis, 1993). Scoring, interpretation and recommended cut-offs Raw scores on the nine subscales and the GSI are calculated by summing the values for the items in each dimension (including four additional items for the GSI) and then dividing by the number of endorsed items in that dimension. The Positive Symptom Total is calculated based on the total count of the number of non-zero items endorsed and reveals the number of symptoms the respondent reports experiencing. The Positive Symptom Distress Index is calculated by summing the values of the items receiving non-zero responses divided by the Positive Symptom Total. This index provides information about the average level of distress the respondent experiences. An individual must answer at least 40 items of the BSI and must not provide the same response for every item on the measure for the responses to be considered a valid administration of the test. T-scores are calculated by comparing a given raw score to the normative tables which are calculated with data from a population generally provided with the measure. T-scores for a given instrument and for a certain population have a mean of 50 and standard deviation of 10. This means that the vast majority (97.7%) of individuals from that same population would have a T-score less than 70. Any individual scoring higher than 70 would be considered to have an unusually high score compared to the population for which the Tscores were calculated. An unusually low T-score would be 30 or less. Frequently, a cut-off T-score of 65 is used in identifying very high scores. Only about 7% of the referent population would score higher than a T-score of 65. To calculate an individual's T-score relative to a given raw score it is necessary to have a population to which his or her score is compared. Typically tables which present the raw scores from a population and the associated T-score are published with the measure. These tables are called norms. If the mean and standard deviation of the population's raw scores of a measure are provided, a z-score can be calculated (raw score subtract the population mean raw score divided by the population standard deviation) and converted to a T-score by multiplying by 10 and adding 50. 8
The BSI manual provides norms based on four groups each separated for males and females: adult non-patients, adult psychiatric outpatients, adult psychiatric inpatients and adolescent non-patients. The test author advises that the Global Severity Index is the scale that is the most sensitive single indicator of distress. The author has not set cut-off scores to determine when further evaluation is warranted. He does advise, however, that using the reference group of adult non-patients a T-score of 63 or above on the GSI or a T-score of 63 and above on any two dimensions would be considered a “case” worthy of further evaluation. This report examined the percentage of offenders who fell at or above a T-score of 65 since the mental health division of CSC chose this cut-off to flag a case for follow up. Some psychologists, however, may opt for a more liberal criterion to reduce the chance of over looking offenders who may require additional services. The results, therefore, also present the percentage of offenders who would meet a T60 criterion. An individual with a given raw score will receive different T-scores depending upon the population on which the scores are normed. For example, a raw score of 0.68 on the Global Severity Index could place the offender at the 93 rd percentile using non patient norms which is a high score, but at the 46 th percentile compared to an in-patient population, a moderate score. Deciding which population is a suitable comparison is not always straight- forward. Although there is evidence of substantial mental disorder among offenders, they are not a psychiatric population so for this project the adult non patient group was chosen as the reference population. Estimates using the T-65 cut-off for the outpatient and in-patient psychiatric norms are also provided in order to compare the degree of distress of federal offenders to that of psychiatric populations. Given the large number of federal offenders who completed this assessment and the uniqueness of the population it was feasible to develop norms relevant to this population. To develop the CSC norms for male offenders on the scales and the GSI of the BSI, a large sample was selected to represent the population of male CSC offenders and estimate the population mean and variability of the scale and GSI scores. For example, the mean raw score on the GSI of 0.69 was rescaled to a normative distribution of 50. The standard deviation of the distribution of raw scores was rescaled to be 10. The raw score that corresponds to a given T-score is calculated through the following formula: Raw Score = raw mean + [(given T-score - 50) (raw score standard deviation)]/10. Further research is required to identify meaningful cut-off scores using the CSC norms. 9
Page 1: _________ Research Report__________
Page 5: Acknowledgements The authors would
Page 9: Table of Contents Acknowledgements
Page 13: List of Figures Figure 1. Frequency
Page 17 and 18: Introduction Mental health problems
Page 19 and 20: This research report provides the r
Page 21 and 22: (Kroner & Weekes, 1996). In additio
Page 23: Obsession-Compulsion (thoughts and
Page 27 and 28: Procedure For the pilot, the CoMHIS
Page 29 and 30: Table 1 Demographic Profile of CoMH
Page 31 and 32: Table 2 Risk-Need Profile of CoMHIS
Page 33 and 34: Table 3 Alcohol and Drug Use Among
Page 35 and 36: These tables apply the non patient
Page 37 and 38: Table 6 BSI Results by Aboriginal S
Page 39 and 40: Table 8 BSI Results by Aboriginal S
Page 41 and 42: eception. Similar to the BSI, a T-s
Page 43 and 44: Table 11 DHS Results by Aboriginal
Page 45 and 46: Table 14 Results of CoMHISS by Rece
Page 47 and 48: However, 3.0% (27) of the offenders
Page 49 and 50: whether they have a current mental
Page 51 and 52: determine the rate of co-occurring
Page 53 and 54: intervention immediately on entry i
Page 55 and 56: References Aroian, K.J., Patsdaught
Page 57 and 58: Skinner, H. A. & Horn, J.L., (1984)
Page 59 and 60: Sub Scale N Mean T-score ≥ 60 % (
Page 75 and 76:
Sub Scale N Mean T-score ≥ 60 % (
Page 77 and 78:
Appendix K: CSC Norms for Male Offe
Page 79:
Screen Reader Descriptions for Grap
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